Conduct uniaxial and biaxial creep experiments in order to develop a data base for long term behavior at 37 degrees centigrade. The conditions will be delineated under which time-temperature superposition may or may not be valid. Cyclic biaxial behavior experiments will be performed in various environments including human blood plasma. Strain energy dissipation and biaxial creep will be assessed. Durability under accelerated cyclic uniaxial and biaxial loading at room temperature and 37 degrees centigrade for various environments, including humal blood plasma, will be determined for selected polymers. Fatigue lives at various stress levels, as well as endurance limits, will be determined for uniaxial tension-tension and tension-compression as well as biaxial deformation modes. A reliable model for fatigue of selected biomaterials will be attempted by correlating fatigue behavior with uniaxial creem and static mechanical behavior.